The process you're referring to is "ring vaccination", and is quite commonly used in epidemiology to limit the spread of outbreaks from a known point source. Th

The process you're referring to is "ring vaccination", and is quite commonly used in epidemiology to limit the spread of outbreaks from a known point source. They are however quite resource intensive to implement - you have to do tons of contact tracing to know who belongs in the net. It would be extremely difficult to do something like that for those avoiding routine childhood vaccinations.